The invention concerns an ancillary device with at least one rotating workpiece holder for removing abrasive from externally accessible cavities inside such large workpieces as engine blocks, transmission housings, etc. once they have been sand blasted in a centrifugal-jet system.
It is known to rotate workpieces that have been sand blasted in a centrifugal-jet system by means of a rotating workpiece holder in order to allow the abrasive to trickle out and be removed from the externally accessible cavities. The workpieces can be secured for example by clamping or in cages (cf. German Patent No. 2 522 620) and accordingly rotated. It has been demonstrated that removing the abrasive from the accessible spaces inside complex workpieces once they have been sand blasted is more difficult than the blasting itself. Particularly problematic are curved water reservoirs in automotive cylinder heads and engine housings.
Abrasive-removing stations integrated into the sand blasting systems are not adequate for such large and complex workpieces because all the rotations involved in the blasting process may not be at satisfactory angles for abrasive removal.